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Currently, tyres are made using a process called vulcanisation, which involves crisscrossing rubber molecules using sulfur and heat – a bit like a pile of wet spaghetti: whenever the pasta cross over they stick together. The process makes rubber stronger and more elastic – perfect for tyres. The downside is if something pierces the tyre, the covalent bond holding it together is permanently lost, which is why tyres can’t self heal.

To get around the problem, a group of exceptionally clever people in Germany opted to use a different technique to vulcanisation with the more commonly used bromobutyl rubber, which as you (obviously) already know contains bromine. Stick with me here: rather than using sulfur to create the crisscross effect, they swapped the bromine atoms for chemical groups called imidazolium bromide, which form charged ionic bonds instead of covalent bonds. In English, this means that if something tears these bonds apart – like a nail in a tyre – they can reform when the charged components come back near each other, meaning the material can “heal” itself.

The scientists put this new material to the test, and found they were able to repair a cut at room temperature – and heating the rubber made the process even quicker. There are already suggestions that this material could be made even stronger, and go on to create a tyre that can fix itself while the car is parked.